1. Field of the Invention
The present invention is directed to windshield wiper blade assemblies for vehicular windshields, and more particularly, toward windshield wiper blade assemblies having curved surfaces for generating an aerodynamic antilift force.
2. Background Art
Numerous attempts have been made at improving the antilift characteristics of a conventional windshield wiper blade through the attachment of air deflecting surfaces to the wiper arm or to the wiper blade assembly. One approach has been to attach an air deflector to the superstructure of the wiper blade assembly. Such designs have proven costly, difficult to manufacture, and are not feasible for retrofitting existing vehicles without replacing the entire wiper blade superstructure. Another approach has been to form the air deflecting surface on the wiping element, but this proved impractical and did not work well.
An alternative approach to solving this problem has been to form the air deflecting surface integrally with a flexible stiffening structure, known in the art as a flexor or backing strip, which flexor interconnects the wiper superstructure and the wiping element. While this proposal provides a simpler construction and facilitates the installation of antilift features within existing wiper assemblies, it has not been possible to form such flexors without degrading critical aspects of the current wiper blade performance or installation capability. In particular, in order to assemble the superstructure containing the airfoil, openings had to be provided in the airfoil through which the attaching claws had to extend resulting in breaks in the airfoil surface with the resulting deterioration of the airfoil affect.
The purpose of providing a flexible stiffening member such as a flexor on the wiping element of a wiper blade assembly is to allow the wiping element to completely conform to the generally nonplanar geometry of a vehicular windshield throughout the full wipe pattern on the windshield. By integrally forming the deflecting surface directly on the flexor, the flexural capability of the flexor, and, hence, the ability of the wiper to conform to the shape of the windshield and thereby optimize the windshield clearing capability of the wiper has in the past been degraded.
The present invention is directed toward overcoming one or more of the problems discussed above.